On the last point, if the sporting activities involve exposure to shocks / heavy vibration, then it should really be a quartz watch, no? ;-) On the other hand, if the concern is more about scratches and general wear, then the Sinn is a very good option. But of course, to a mechanical watch lover, quartz often just does not have the right feel. I admit that I'm occasionally wearing my Damasko (not a dive watch per se, but 100m WR), which I got for purposes similar to your Sinn, in situations I probably shouldn't. But the ice-hardened steel of Damasko really works - I cannot see even hairline scratches in the case or bracelet after several years of (occasional) use.